Problem: A rectangle is $4$ centimeters long. The rectangle is also $2$ centimeters wide. What is its perimeter?
Explanation: $4\text{ cm}$ $2\text{ cm}$ The perimeter is the total length of all the sides of the shape added together. Add up the lengths of the sides: $ \text{perimeter} = {2} + {4} + {2} + {4} $ $ \text{perimeter} = 12\text{ cm} $